With the booming development of flat panel display technology, an AMOLED (Active Matrix Organic Light Emitting Diode) display, compared with traditional liquid crystal displays (LCD), has excellent features, such as being self-luminous so that a backlight is not needed, low power consumption, no visual angle restriction, and high response rate. In addition, AMOLED displays have lighter weight and thinner thickness. As a result, the AMOLED display is expected to dominate in the next generation of flat panel display technology and to be used more widely.
Currently AMOLED display panels comprise an upper substrate and a lower substrate, where the upper substrate and the lower substrate are bonded together by a glass frit layer on the edge encapsulation areas of the substrates. A visible test, i.e. VT test, is typically carried out after the panel is manufactured. During this VT test, the picture luminance is increased in the display area of the display panel, and the luminance is achieved generally by increasing the current of the circuit of the display panel. It is quite difficult to change the resistance of the circuit of the display panel, since the display panel has been properly manufactured. As a result, increasing the picture luminance is achieved generally by increasing the input voltage. But when the VT test is performed, heat is generated in some elements or devices in the circuit of the display panel if the input voltage is increased, and in particular, more heat is generated in an electrode with relatively small cross-sectional area and relatively large resistance. Some of the electrodes partially overlap with the glass frit layer in the encapsulation area, so that heat is transmitted to the glass frit layer by the heated electrode, and the glass frit layer may be seared. This may affect the encapsulation efficacy and the performance of the display during the VT test.